Electrical energy management of heat transfer devices for vehicles

ABSTRACT

Energy management techniques for heating or cooling a surface of a component of a vehicle comprise determining a heating lag time indicative of a lag time for a surface element of the vehicle component to heat to a first target temperature in response to a power on-off or power off-on modulation of a heat transfer component, determining a cooling lag time indicative of a lag time for the surface element to cool to a second target temperature in response to a power on-off or power off-on modulation of the heat transfer component, and controlling power-on and power-off times of the heat transfer component based on the determined heating and cooling lag times so as to not require a temperature sensor for feedback-based temperature control.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. App. No. 16/676,631 filed onNov. 7, 2019, the contents of which are incorporated herein by referencethereto.

FIELD

The present application generally relates to vehicle heat transferdevices and, more particularly, to electrical energy management ofheated and cooled surface devices for vehicles.

BACKGROUND

A vehicle heat transfer device includes a heat transfer component(electrical heating element, a cooling compressor/pump, a cooling fan,etc.) that is configured to generate and provide heat energy to orremove heat energy from a surface formed of a material to beheated/cooled. Conventional vehicle heated surface devices, for example,typically operate by a controller commanding the temperature of theelectrical heating element to a target temperature of the surface andthen maintaining electrical heating element at this target temperature.This approach consumes energy directly proportional to the power of theelectrical heating element and the time the electrical heating elementis active or “powered-on” and is generating heat energy to heat thesurface material. The same could also be true for cooled surfacedevices. Therefore, this conventional approach could potentially resultin excessive power consumption. Accordingly, while such conventionalvehicle heat transfer devices do work well for their intended purpose,there remains a need for improvement in the relevant art.

SUMMARY

According to one example aspect of the invention, a system for heatingor cooling a surface of a component of a vehicle is presented. In oneexemplary implementation, the system comprises: an heat transfercomponent configured to modulate (i) between a power-on state where heatenergy is being generated and a power-off state where heat energy is notbeing generated or (ii) between a power-on state where heat energy isbeing removed and a power-off-state where heat energy is not beingremoved, a surface element of the vehicle component, the surface elementbeing formed of a material to be heated by the heat energy generated andprovided by the heat transfer component or to be cooled by the heatenergy removed by the heat transfer component, and a control systemconfigured to: determine a heating lag time indicative of a lag time forthe surface element to heat to a first target temperature in response toa power on-off or power off-on modulation of the heat transfercomponent, determine a cooling lag time indicative of a lag time for thesurface element to cool to a second target temperature in response to apower on-off or power off-on modulation of the heat transfer component,and control power-off and power-on times of the heat transfer componentbased on the determined heating and cooling lag times so as to notrequire a temperature sensor for feedback-based temperature control.

In some implementations, the heat transfer component is configured togenerate and provide heat energy to the surface element while in thepower-on state and to not generate or provide heat energy to the surfaceelement while in the power-off state, the heating lag time is determinedas the lag time for the surface element to heat to the first targettemperature in response to the power off-on modulation of the heattransfer component, and the cooling lag time is determined as the lagtime for the surface element to cool to the second target temperature inresponse to the power on-off modulation of the heat transfer component.In some implementations, the control system is configured to set aminimum power-on time of the heat transfer component based on thedetermined heating lag time and to set a maximum power-off time of theheat transfer component based on the determined cooling lag time. Insome implementations, the minimum power-on and maximum power-off timesprovide for a desired amount of surface element temperature heating andcooling during modulation between power-on and power-off states of theheat transfer component, and wherein the desired amount of surfaceelement temperature heating and cooling is sufficient to maintain astable temperature of the surface element within a desired temperaturerange. In some implementations, the heated surface component of thevehicle is one of a heated mirror, a heated glass panel, a heated seat,and a heated steering wheel.

In some implementations, the heat transfer component is configured toremove heat energy from the surface element while in the power-on stateand to not remove heat energy from the surface element while in thepower-off state, the heating lag time is determined as the lag time forthe surface element to heat to the first target temperature in responseto the power on-off modulation of the heat transfer component, and thecooling lag time is determined as the lag time for the surface elementto cool to the second target temperature in response to the power off-onmodulation of the heat transfer component. In some implementations, thecontrol system is configured to set a maximum power-off time of the heattransfer component based on the determined heating lag time and to set aminimum power-on time of the heat transfer component based on thedetermined cooling lag time. In some implementations, the minimumpower-on and maximum power-off times provide for a desired amount ofsurface element temperature heating and cooling during modulationbetween power-on and power-off states of the heat transfer component,and wherein the desired amount of surface element temperature heatingand cooling is sufficient to maintain a stable temperature of thesurface element within a desired temperature range. In someimplementations, the cooled surface component of the vehicle is one of acooled seat, a cooled steering wheel, a cooled battery pack, and acooled power inverter.

According to another example aspect of the invention, an energymanagement method for heating or cooling a surface of a component of avehicle is presented. In one exemplary implementation, the methodcomprises: determining, by a control system, a heating lag timeindicative of a lag time for a surface element of the vehicle componentto heat to a first target temperature in response to a power on-off orpower off-on modulation of a heat transfer component, wherein the heattransfer component is configured to modulate (i) between a power-onstate where heat energy is being generated and a power-off state whereheat energy is not being generated or (ii) between a power-on statewhere heat energy is being removed and a power-off state where heatenergy is not being removed, and wherein the surface element is formedof a material to be heated by the heat energy generated and provided bythe heat transfer component or to be cooled by the heat energy removedby the heat transfer component, determining, by the control system, acooling lag time indicative of a lag time for the surface element tocool to a second target temperature in response to a power on-off orpower off-on modulation of the heat transfer component, and controlling,by the control system, power-on and power-off times of the heat transfercomponent based on the determined heating and cooling lag times so as tonot require a temperature sensor for feedback-based temperature control.

In some implementations, the heat transfer component is configured togenerate and provide heat energy to the surface element while in thepower-on state and to not generate or provide heat energy to the surfaceelement while in the power-off state, the heating lag time is determinedas the lag time for the surface element to heat to the first targettemperature in response to the power off-on modulation of the heattransfer component, and the cooling lag time is determined as the lagtime for the surface element to cool to the second target temperature inresponse to the power on-off modulation of the heat transfer component.In some implementations, controlling the power-on and power-off times ofthe heat transfer component comprises setting a minimum power-on time ofthe heat transfer component based on the determined heating lag time andsetting a maximum power-off time of the heat transfer component based onthe determined cooling lag time. In some implementations, the minimumpower-on and maximum power-off times provide for a desired amount ofsurface element temperature heating and cooling during modulationbetween power-on and power-off states of the heat transfer component,and wherein the desired amount of surface element temperature heatingand cooling is sufficient to maintain a stable temperature of thesurface within a desired temperature range. In some implementations, theheated surface component of the vehicle is one of a heated mirror, aheated glass panel, a heated seat, and a heated steering wheel.

In some implementations, the heat transfer component is configured toremove heat energy from the surface element while in the power-on stateand to not remove heat energy from the surface element while in thepower-off state, the heating lag time is determined as the lag time forthe surface element to heat to the first target temperature in responseto the power on-off modulation of the heat transfer component, and thecooling lag time is determined as the lag time for the surface elementto cool to the second target temperature in response to the power off-onmodulation of the heat transfer component. In some implementations,controlling the power-on and power-off times of the heat transfercomponent comprises setting a maximum power-off time of the heattransfer component based on the determined heating lag time and settinga minimum power-on time of the heat transfer component based on thedetermined cooling lag time. In some implementations, the minimumpower-on and maximum power-off times provide for a desired amount ofsurface element temperature heating and cooling during modulationbetween power-on and power-off states of the heat transfer component,and wherein the desired amount of surface element temperature heatingand cooling is sufficient to maintain a stable temperature of thesurface element within a desired temperature range. In someimplementations, the cooled surface component of the vehicle is one of acooled seat, a cooled steering wheel, a cooled battery pack, and acooled power inverter.

Further areas of applicability of the teachings of the presentdisclosure will become apparent from the detailed description, claimsand the drawings provided hereinafter, wherein like reference numeralsrefer to like features throughout the several views of the drawings. Itshould be understood that the detailed description, including disclosedembodiments and drawings referenced therein, are merely exemplary innature intended for purposes of illustration only and are not intendedto limit the scope of the present disclosure, its application or uses.Thus, variations that do not depart from the gist of the presentdisclosure are intended to be within the scope of the presentdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram of an example vehicle having one ormore heat transfer devices according to the principles of the presentdisclosure;

FIG. 2 is a functional block diagram of an example vehicle heat transferdevice according to the principles of the present disclosure;

FIG. 3 is a timing diagram illustrating heating and cooling lag timedeterminations relative to electrical heating element power-on andpower-off times according to the principles of the present disclosure;and

FIGS. 4A-4B are flow diagrams of example energy management methods forheated surface and cooled surface configurations of a vehicle heattransfer device, respectively, according to the principles of thepresent disclosure.

DETAILED DESCRIPTION

As previously discussed, conventional vehicle heat transfer devicescommand a heat transfer component (an electrical heating element, acooling compressor/pump, a cooling fan, etc.) to generate and provideheat energy to or remove heat energy from a surface material. For aheated surface device, for example, an electrical heating element may becommanded to generate heat energy equal to a target temperature of thesurface material. This approach consumes energy directly proportional tothe power of the electrical heating element and the time the electricalheating element is active or “powered on” and thus could result inexcessive power consumption. The same could also be true for cooledsurface devices. One or more temperature sensors could be implemented toperform closed-loop feedback-based temperature control, but thesesensors increase costs. Accordingly, an improved vehicle heat transferdevice and an energy management method for the same are presented. Theimproved techniques implemented by these systems and methods involveinitially determining heating and cooling lag times, which areindicative of times for the surface material to change temperature by acertain amount in response to power-on to power-off transitions orvice-versa. Once determined, the heating and cooling lag times areutilized to optimally control power-on and power-off times of the heattransfer component. In a heated surface implementation, a minimumpower-on time could be set based on the heating lag time and a maximumpower-off time could be set based on the cooling lag time. Conversely,in a cooled surface implementation, a minimum power-on time could be setbased on the cooling lag time and a maximum power-off time could be setbased on the heating lag time.

Referring now to FIG. 1 , a functional block diagram of a vehicle 100having at least one heat transfer device (generally referred to hereinas “heated transfer device(s) 200”) is illustrated. As previouslydiscussed herein, it will be appreciated that the term “heat transferdevice” comprises both heated surface devices and cooled surfacedevices. The vehicle 100 includes at least one of a heated mirror 200 a,a heated glass panel 200 b (a front windshield, a rear windshield orbacklight, etc.), a heated or cooled seat 200 c, a heated or cooledsteering wheel 200 d, a cooled battery pack 200 e, a cooled powerinverter 200 f, and one or more other heat transfer devices 200 g(collectively, “heat transfer device(s) 200) and a controller or controlsystem 204. It will be appreciated that these are non-limiting examplesof vehicle heat transfer device(s) 200 and that the techniques of thepresent disclosure are applicable to any suitable interior or exteriorvehicle heat transfer device (headlights, taillights, grilles/radomes,interior door panels, a dash/infotainment system, etc.) or any othervehicle components that require heating or cooling. It will also beappreciated that the vehicle 100 includes a plurality of typicalcomponents that are not illustrated (a powertrain, a driveline, etc.).The controller 204 controls operation of the heat transfer device(s)200. An external calibration system 104 could be utilized, e.g., inconjunction with one or more temperature sensors, to determine theheating and cooling lag times of the heat transfer device(s) 200 (e.g.,during vehicle development or calibration), which could then be providedto the controller 104. Alternatively, the controller 204 could initiallydetermine the heating and cooling lag times in a similar manner forlater use. The calibration system 104 and/or the controller 204 are alsoreferred to herein as a “system” associated with the vehicle 100 and theheat transfer device(s) 200.

Referring now to FIG. 2 , a functional block diagram of an exampleconfiguration of one of the heat transfer device(s) 200 (e.g., devices200 a-200 g) is illustrated. The heat transfer device 200 comprises thecontroller 204 and a heat transfer component 208 (or system ofcomponents) that is configured to modulate between a power-on statewhere it generates or removes heat energy (e.g., in response to aprovided current) and a power-off state where it does not generate orremove heat energy. The heat transfer component 208 could be anysuitable type of electrical heating element (metal, ceramic,semiconductor, thick film, etc.) configured to generate heat energy inresponse to receiving electrical energy or any suitable type of coolingcomponent/system (a compressor and a pump for a liquid coolant, a fan,etc.) configured to remove heat energy in response to receivingelectrical energy. A surface or surface element 212 of the heat transferdevice 200 is formed of a non-dynamic or non-changing material (plastic,glass, leather, etc.) that is configured to be heated by the heat energygenerated by or cooled by the heat energy removed by the heat transfercomponent 208. The controller 204 could be integrated into or externalto the heat transfer device 200 and is configured to control the heattransfer component 208 (e.g., modulation between power-on and power-off)to control a temperature of the surface 212 as desired. It will beappreciated that the controller 204 could operate based on inputs fromone or more external sensors 216 (an ambient temperature sensor, avehicle seat weight sensor, etc.), which could be part of the heattransfer device 200 or external thereto. As previously described, asurface temperature sensor could be temporarily implemented (e.., bycalibration system 104 or control system 204) only for the initialheating/cooling lag time determinations. As previously mentioned,however, the techniques of the present disclosure also do not requiresuch surface temperature sensor(s) for closed-loop feedback-basedtemperature control, thereby saving costs.

Referring now to FIG. 3 , a timing diagram 300 illustrating heating andcooling lag times for a heated surface configuration of an examplevehicle heat transfer device are illustrated. For purposes of describingFIG. 3 , the heat transfer component 208 will be temporarily referred toas “electrical heating element 208.” In the left portion of FIG. 3 , theelectrical heating element 208 is initially in a power-on state and itstemperature is increasing along with the temperature of the surface 212.As shown, the cooling lag period begins at the second on-off modulationof the electrical heating element 208 (where its current drops to zeroor some other minimal level). This cooling lag time represents theamount of time that it takes for the temperature of the surface 212 tobegin decreasing or to decrease by a desired amount after the poweron-off transition of the electrical heating element 208. In the leftportion of FIG. 3 , the cooling lag period is illustrated by the twovertical dashed lines. In the right portion of FIG. 3 , the electricalheating element 208 initially has a power on-off transition ormodulation and its temperature is decreasing along with the temperatureof the surface 212. As shown, the heating lag period begins at the firstoff-on modulation of the electrical heating element 208 (where itscurrent increases from its minimal level to a maximum or full-on level).This heating lag time represents the amount of time that it takes forthe temperature of the surface 212 to begin increasing or to increase bya desired amount after the off-on transition of the electrical heatingelement 208. In the right portion of FIG. 3 , the heating lag period isillustrated by the two dashed vertical lines.

It will be appreciated that while the techniques herein are primarilydescribed herein with specific reference to heated surfaceconfigurations of the heat transfer device(s) 200, such as in thedescription above with respect to timing diagram 300 of FIG. 3 , thetechniques could of the present disclosure are also be applicable tocooled surface configurations of heat transfer devices of vehicles aspreviously mentioned and illustrated herein (cooled seats, a cooledsteering wheel, a cooled battery pack, a cooled power inverter, etc.).For example, heating and cooling lag times for a cooled surfaceconfiguration of a heat transfer device having a surface and a suitableheat transfer device configured for cooling or removing heat energy(e.g., a compressor and/or a pump that control a flow of a liquidcoolant, or a fan) could be determined and then utilized to controlpower-on/power-off or other actuation times of the heat transfercomponent in order to accurately maintain the surface temperature at adesired level or within a desired range. Generic flowcharts for bothheated surface and cooled surface configurations of vehicle heattransfer devices are illustrated in FIGS. 4A-4B and will now bedescribed in greater detail.

Referring now to FIG. 4A, a flow diagram of a method 400 forestablishing or determining heating and cooling lag times for bothheated and cooled surface configurations of vehicle heat transferdevices is illustrated. While the method 400 specifically referencesheat transfer device(s) 200, it will be appreciated that this method 400could be applicable to any suitable heat transfer device. At 404, theheat transfer component 208 is cycled or modulated at a range of ambienttemperatures. For a heated surface configuration, the heat transfercomponent 208 is commanded to a power-on (ON) state and for a cooledsurface configuration, the heat transfer component 208 is commanded to apower-off (OFF) state. At 408, the time interval or delay between aparticular temperature increase of the heat transfer component 208 andthe same particular temperature increase of the surface 212 is measuredto determine the heating lag time. The determined heating lag time isthen stored at 412 (e.g., in a datastore or memory of the controller204) and associated with a particular ambient temperature or range ofambient temperatures. At 416, it is determined whether a desired rangeof temperature deltas have been measured. When true, the method 400proceeds to 420. Otherwise, the method 400 returns to 404 for furthermodulation/measurement/storage.

At 420, the heat transfer component 208 is cycled or modulated at arange of ambient temperatures. This time, for a heated surfaceconfiguration, the heat transfer component 208 is commanded to apower-off (OFF) state and for a cooled surface configuration, the heattransfer component 208 is commanded to a power-on (ON) state. At 424,the time interval or delay between a particular temperature decrease ofthe heat transfer component 208 and the same particular temperaturedecrease of the surface 212 is measured to determine the cooling lagtime. The determined cooling lag time is then stored at 412 andassociated with a particular ambient temperature or range of ambienttemperatures. At 428, it is determined whether a desired range oftemperature deltas have been measured. When true, the method 400 ends.Otherwise, the method 400 returns to 420 for furthermodulation/measurement/storage.

The following table is merely an example of heating and cooling lagtimes and the associated data that could be stored at 412 for a heatedsurface configuration of a vehicle heat transfer device, includingambient temperatures in both degrees (°) Fahrenheit (F) and Celsius (C)and times in either minutes (min) or seconds (sec).

Ambient Temp. Heating Time Heating Lag Time Cooling Lag Time -20° F.(-28.89° C.) 25 min. 0 sec. 0 sec. -10° F. (-23.33° C.) 20 min. 15 sec.5 sec. -4° F. (-20° C.) 15 min. 10 sec. 5 sec. 0° F. (-17.78° C.) 10min. 10 sec. 5 sec. 14° F. (-10° C.) 8 min. 10 sec. 5 sec. 25° F.(-3.89° C.) 6 min. 10 sec. 5 sec.

This stored information could then be utilized to control modulation ofthe heat transfer component 208 of the heat transfer device(s) 200,which will now be described in greater detail with respect to theflowchart of FIG. 4B.

Referring now to FIG. 4B, a flow diagram of a method 450 for usingheating and cooling lag times for both heated and cooled surfaceconfigurations of vehicle heat transfer devices is illustrated. Whilethe method 450 specifically references heat transfer device(s) 200, itwill be appreciated that this method 400 could be applicable to anysuitable heat transfer device. At 412, the stored data from block/step412 of method 400 (FIG. 4A) is retrieved for usage. At 454, it isdetermined whether conditions for performing the control method havebeen achieved. This could include, for example only, a sufficient amountof data having been obtained and stored at 412 in order to properlycontrol modulation of the heat transfer component 208. When true, themethod 450 proceeds to 458. Otherwise, the method 450 ends or returns(e.g., to method 400 of FIG. 4A, to obtain additional data). At 458, theheat transfer component 208 is commanded for the cooling lag time. For aheated surface configuration, the heat transfer component 208 iscommanded to a power-off (OFF) state and for a cooled surfaceconfiguration, the heat transfer component 208 is commanded to apower-on (ON) state.

At 462, it is determined whether the cooling lag time has expired (e.g.,a corresponding timer). When true, the method 450 proceeds to 466.Otherwise, the method 450 returns to 458. At 466, the heat transfercomponent is commanded for the heating lag time. This time, for a heatedsurface configuration, the heat transfer component 208 is commanded to apower-on (ON) state and for a cooled surface configuration, the heattransfer component 208 is commanded to a power-off (OFF) state. At 470,it is determined whether the heating lag time has expired (e.g., acorresponding timer). When true, the method 450 proceeds to 474.Otherwise, the method 450 returns to 466. At 474, it is determinedwhether conditions for the control time have completed. This couldinclude, for example only, a certain number of cycles or iterationshaving been performed, or a heating/cooling request for the vehicle heattransfer device being withdrawn or otherwise disabled by a driver of thevehicle. When true, the method 450 is disabled or ends. When false,however, the process continues and the method 450 returns to 458.

While heated surface and cooled surface configurations are described asseparate or distinct configurations herein, it will be appreciated thata vehicle heat transfer device could have both heated surface and cooledsurface configurations (e.g., a heated and cooled vehicle seat) and thuscould determine separate sets of heating and cooling lag times for twodifferent heat transfer components/systems. When operating in a heatingmode, one set of heating/cooling lag times could be utilized and whenoperating in a cooling mode, another different set of heating/coolinglag times could be utilized. These heating/cooling lag times coulddiffer because the heat energy generated by and the heat energy removedby the different heat transfer components could occur at differentrates.

It will be appreciated that the term “controller” as used herein refersto any suitable control device or set of multiple control devices thatis/are configured to perform at least a portion of the techniques of thepresent disclosure. Non-limiting examples include anapplication-specific integrated circuit (ASIC), one or more processorsand a non-transitory memory having instructions stored thereon that,when executed by the one or more processors, cause the controller toperform a set of operations corresponding to at least a portion of thetechniques of the present disclosure. The one or more processors couldbe either a single processor or two or more processors operating in aparallel or distributed architecture.

It should also be understood that the mixing and matching of features,elements, methodologies and/or functions between various examples may beexpressly contemplated herein so that one skilled in the art wouldappreciate from the present teachings that features, elements and/orfunctions of one example may be incorporated into another example asappropriate, unless described otherwise above.

What is claimed is:
 1. An energy management method for heating orcooling a surface of a component of a vehicle, the method comprising:determining, by a control system, a heating lag time indicative of a lagtime for a surface element of the vehicle component to heat to a firsttarget temperature in response to a first power on-off or power off-onmodulation of a heat transfer component, wherein the heat transfercomponent is configured to modulate (i) between a power-on state whereheat energy is being generated and a power-off state where heat energyis not being generated or (ii) between a power-on state where heatenergy is being removed and a power-off state where heat energy is notbeing removed, and wherein the surface element is formed of a materialto be heated by the heat energy generated and provided by the heattransfer component or to be cooled by the heat energy removed by theheat transfer component; determining, by the control system, a coolinglag time indicative of a lag time for the surface element to cool to asecond target temperature in response to a second power on-off or poweroff-on modulation of the heat transfer component; and controlling, bythe control system, power-on and power-off times of the heat transfercomponent based on the determined heating and cooling lag times so as toperform feedback-based temperature control without requiring atemperature sensor.
 2. The method of claim 1, wherein: the heat transfercomponent is configured to generate and provide heat energy to thesurface element while in the power-on state and to not generate orprovide heat energy to the surface element while in the power-off state;the heating lag time is determined as the lag time for the surfaceelement to heat to the first target temperature in response to the firstpower off-on modulation of the heat transfer component; and the coolinglag time is determined as the lag time for the surface element to coolto the second target temperature in response to the second power on-offmodulation of the heat transfer component.
 3. The method of claim 2,wherein controlling the power-on and power-off times of the heattransfer component comprises setting a minimum power-on time of the heattransfer component based on the determined heating lag time and settinga maximum power-off time of the heat transfer component based on thedetermined cooling lag time.
 4. The method of claim 3, wherein theminimum power-on and maximum power-off times provide for a desiredamount of surface element temperature heating and cooling duringmodulation between power-on and power-off states of the heat transfercomponent, and wherein the desired amount of surface element temperatureheating and cooling is sufficient to maintain a stable temperature ofthe surface within a desired temperature range.
 5. The method of claim2, wherein the vehicle component is one of a heated mirror, a heatedglass panel, a heated seat, and a heated steering wheel.
 6. The methodof claim 1, wherein: the heat transfer component is configured to removeheat energy from the surface element while in the power-on state and tonot remove heat energy from the surface element while in the power-offstate; the heating lag time is determined as the lag time for thesurface element to heat to the first target temperature in response tothe first power on-off modulation of the heat transfer component; andthe cooling lag time is determined as the lag time for the surfaceelement to cool to the second target temperature in response to thesecond power off-on modulation of the heat transfer component.
 7. Themethod of claim 6, wherein controlling the power-on and power-off timesof the heat transfer component comprises setting a maximum power-offtime of the heat transfer component based on the determined heating lagtime and setting a minimum power-on time of the heat transfer componentbased on the determined cooling lag time.
 8. The method of claim 7,wherein the minimum power-on and maximum power-off times provide for adesired amount of surface element temperature heating and cooling duringmodulation between power-on and power-off states of the heat transfercomponent, and wherein the desired amount of surface element temperatureheating and cooling is sufficient to maintain a stable temperature ofthe surface element within a desired temperature range.
 9. The method ofclaim 6, wherein the vehicle component is one of a cooled seat, a cooledsteering wheel, a cooled battery pack, and a cooled power inverter.